T-cell Repertoire and Thymus
- P. Marrack*,†,‡,§,**,
- M. Blackman*,†,
- H.-G. Burgert*,†,
- J.M. McCormack*,
- J. Cambier‡,¶,
- T.H. Finkel†, and
- J. Kappler†,‡,**
- *Howard Hughes Medical Institute at Denver, †Department of Medicine, and ¶Department of Pediatrics, National Jewish Center, Denver, Colorado 80206; ‡Departments of Microbiology and Immunology, §Biochemistry, Biophysics, and Genetics, and **Medicine, University of Colorado Health Sciences Center, Denver, Colorado 80206
This extract was created in the absence of an abstract.
Excerpt
The α/β T-cell repertoire in any given animal is known to be affected by four factors: the germ line genes available for receptor construction (Vα, Jα, Vβ, etc.), positive selection, self-tolerance, and exposure to foreign antigens. In this paper, we discuss two of these phenomena, namely, positive selection and tolerance due to clonal deletion in the thymus.
More than 10 years ago, Bevan (1977) and Zinkernagel et al. (1978) discovered positive selection—thymocytes that mature in a given animal are much more likely to react with a given foreign antigen associated with self-major histocompatibility complex (MHC) than with the same foreign antigen associated with allogeneic MHC. Positive selection, which has since been demonstrated dramatically in transgenic animals (Kisielow et al. 1988a; Sha et al. 1988), is now thought to involve interaction between the receptors on immature thymocytes and MHC molecules on thymus cortical epithelial (TCE) cells. It is very likely that...
